Wet & Healthy

Bruce E. Becker, MD Clinical Professor, University of Washington School of Medicine

Research Professor, Washington State University Director, National Aquatics & Sports Medicine Institute

beckerb@wsu.edu

The Health Benefits of Aquatic Activity

Aquatic vs. Land Activity

! " Buoyancy creates unique opportunities!! " Multidimensional movement is easy!! " Viscosity adds graded resistance!! " Immersion is usually pleasurable!! " Relaxation is nearly automatic for most!! " The water has its own healing

properties with unique physiologic effects!

Pressure Increases!Neck depth = negligible!

Chest depth = ± 18 mmHg!

Waist depth = ± 36 mmHg!

Thigh depth = ±70 mmHg!

Ankle depth = ±110 mmHg!

Increasing Hydrostatic Force!

Cardiovascular Changes with Immersion

Arborelius, Aerospace Med 43:701-707, 1978; Risch, Pflugers Arch, 374:119-120, 1978!

Cha

nges

dur

ing

imm

ersi

on i

n %!

Thermoneutral water temperature, neck depth!

Water Immersion to !chest or higher!

Increased hydrostatic !pressure!

Venous compression! Lymphatic compression!

Central blood!volume increases!

Atrial pressure!rises!

Pulmonary Arterial !Pressure rises!

Cardiac volume!increases!

Stroke!volume increases!

Cardiac output! increases!

Vascular Pressures with Immersion

Epstein, Circ Res 39:619-628, 1976!

Muscle Blood Flow with Immersion B

lood

Flo

w in

ml /

min

/ 10

0 gm

. tis

sue!

Balldin, Aerospace Med 42:489-493, 1971!

Nearly a 250% increase in muscle blood flow!

Thermoneutral temperature, neck depth, seated!

Aquatic Therapy Effects on CHF

Tei & Tanaka, J Cardiol 1996:27:29-30!

4 week therapy course!

Ejection Fraction in %!

LV Dimension in mm!

CT Ratio in %!

Neck depth immersion at 41° C (105.8° F)!

Warm Water Immersion in CHF

Cider A, Svealv BG, Tang MS, Eur J Heart Failure, 8:3, 308-313, 2006!

Cider A, Schaufelberger M, Sunnerhagen KS, Andersson B, Eu J Heart Failure 5 (2003) 527-535!

25 pts with CHF, 8 weeks training at 3 times per week!

Renal Hormone Changes with Immersion

Epstein, Murray; Renal effects of head out immersion in humans: a 15-year update; Physiological Reviews. 1992!

PGE2!

Renin!Aldosterone!ADH!

Cha

nges

in %!

Renal Function Changes with Immersion

Epstein, Physiol Rev 72:577, 1992!

Stud

y En

d!

Aquatics & Bone Density!

! " In older male Masters swimmers, increased bone density has been found.!

! " In older female Masters swimmers, no effect has been noted.!

! " In younger individuals, swimming did not add bone mineral content as effectively as weight-bearing exercise.!

Aquarobic Effect on BMD, Fitness & Well-being @1 year!

Bravo, Gauthier et al, Arch PMR, 78, 1375-80,1997!

0%!

77 females, ages 50-70, 1 hour/day, 3 days per week, 12 months!

Osteoporosis and Aquatic Therapy!

! " The aquatic environment is a very appropriate place to begin a strengthening and endurance program!

! " The pool will probably not provide a major bone-deposition stimulus, or reverse loss of bone mineralization!

! " Transitioning to land-based impact activities is the goal for osteoporosis!

Respiratory Motor System:!

•"Congestive Heart Failure!•"Neuromuscular Disease!•"Malnutrition & General Debilitation!

• Neck muscles, incl. Scalenes, SCM!• Diaphragm!• Intercostal muscles!• Abdominal muscles!Impairment seen in:!

Pulmonary Function Divisions!

Expiratory Reserve Volume

Inspiratory Reserve Volume

Tidal Volume

Functional Residual Capacity

Inspiratory Capacity

Vita

l Cap

acity

Residual Volume

Energy Costs of Immersed Breathing

0! 5! 10! 15!

Dynamic Component!

Elastic Component!

Total Work of Breathing (kg-cm)!

Work in Kg/cm.!Hong, J Appl Physiol 27:535-538, 1969!

Neck depth immersion at thermoneutral temperature!

Hydrostatic Pressure!

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Head-out Water Immersion!

PO2! Expiratory flow rate! Pulmonary compliance! Efficiency!

Central blood volume! Chest wall pressure! Abdom. compression!

Pulmonary Vessel fill! Chest circumference! Diaphragm height!

Diffusion capacity! Airway resistance! Lung volume & VC!

Inspiratory Muscle Training

! " Attenuates blood lactate formation !! " Improves exercise recovery time in

repetitive sprint activity!! " Improves perceptual response to

exertion!! " Improves time trial performance,

especially in longer events (4 to 5%)!

6 weeks of daily training!

Romer et al, Int j sports Med 23(5) 2002, MSSE 34(5) 2002!

NSPF / WSU Respiratory Study ! " 100 college students, 50 per group!! "Group 1: Deep water exercise, 50 minutes/

session 3 times per week at RPE 15!! "Group 2: Land aerobics, 50 minutes /

session 3 times per week at RPE 15!! " Data points: prestudy, week 8 and week 15!! "PImax, PImax-VL curves, PFTs!! "% body fat via BodPod!! "Treadmill VO2 max!

Exercise Programming ! "Exercise sessions between groups were

designed to be similar in all aspects!! "Warm-up, aerobic exercise, and cool-down

times were the same between groups!! "Choreography was similar and in the same

order between groups!! "Instructor supervision, motivation and

feedback was similar!! "Students were instructed to maintain a

desired RPE of 15. An RPE of 15 is considered “Hard”!

Study Methods!

! " All subjects were tested first for resting heart rate and bp, then body fat percentage, followed by spirometry, and then finally maximal oxygen consumption.!! " There was no difference between groups on testing times.!! " Subjects self selected their testing time for peak performance.!

Initial Assessment!

Lung Measurements Assessed ! " Peak inspiratory pressure (PImax)!! " Peak expiratory pressure (PEmax)!! "Mean airway pressure (MAP)!! "Mean inspiratory pressure (MIP)!! " Tidal volume (Vt)!! "Forced vital capacity (FVC)!! "Maximal inspiratory flow (MIF)!! "Maximal inspiratory minute volume (VIatph)!! "Maximal expiratory minute volume (VEatph)!! "Maximal expiratory flow (MEF)!

Starting Group Comparisons!

Age! 22.34! 21.04!Gender M/F! 26/25! 30/20!Active (#3 days/wk)! 68%! 62%!% Body Fat! 24.25! 23.67!Weight (Kg)! 79.85! 77.12!BPsys! 122.8! 123.33!BPdia! 67.82! 69.43!HRrest! 90.43! 88.78!VO2max! 42.17! 42.96!

Variable! Water! Land!

Study Results between Groups!

PImax! 183.39! 185.73! p=0.522!PEmax! 194.83! 193.2! p=0.658!MIP! 15.08! 15.68! p=0.802!Vt! 2.73! 2.67! p=0.686!FVC! 3.04! 2.90! p=0.468!MIF! 89.46! 88.14! p=0.802!MEF! 401.87! 396.31! p=0.812!MAP! 14.71! 14.21! p=0.604!

Variable! Water! Land! Significance!

Max Expiratory Vital Capacity (FVC)!Changes between groups across study interval!

Lite

rs! Nonsignificant at p=0.468!

Max Inspiratory Vital Capacity (FIVC) !Changes between groups across study interval!

Statistically significant at p=0.042!

Lite

rs!

Tidal Volume at Max Exercise!Li

ters!

Statistical value p= 0.068!

Study Results: Both Groups!Body Weight! 77.16! 75.1! 75.41! 0.0001!% Body Fat! 24.16! 22.47! 23.18! 0.0001!VO2max! 42.03! 46.2! 45.82! 0.0001!Vt! 1.3! 1.26! 1.05! 0.0001!FVC! 2.97! 4.38! 4.36! 0.0001!FIVC! 3.11! 4.34! 4.32! 0.0001!PEF! 194.11**! 503.53! 511.37! 0.0001!MIF!VIatps! 88.81! 93.82! 90.29! 0.0001!VEatps! 108.75! 117.16! 110.71! 0.0001!MEF!

Variable! Week 0! Week 8! Week 15! Significance!

Preliminary Study Results ! "The aquatic group showed improvement in

ventilatory capacity (FIVC) and respiratory endurance (MVV12 sec) compared to the land group.!

! "Both groups showed statistically significant improvements in:!! "Weight loss and lean body mass!! "% body fat!! "VO2max!! "Resting tidal volume!! "Peak expiratory flow pressures!

The Cocoon Effect!

Probable Causes

! " Autonomic Nervous System downregulation!! "Heart Rate Variability changes!! "Catacholamine changes!! "Blood Pressure changes!! "EEG changes!! "Muscle tone changes!

The WSU Research Questions:

1."What are the effects, potential health benefits and risks of aquatic immersion at various temperatures?!

2."What aquatic temperatures produce the maximum positive effects??!

3."What is the time course of these changes?!

Our Lab •" 3 Prodigy™ tubs, donated by Hot Spring Spas.!–" Cool tub maintained at 88° F (31.1°C)!–" Neutral maintained at 98° F (36.7°C)!–" Warm tub maintained at 102° F (38.9°C)!

•" CorTemp! telemetry system!•" BioPac! monitoring system!–" ECG!–" Blood flow measurement through laser doppler!–" EEG!–" Core temperature!

•" Blood pressure monitoring!•" Body fat percentage (BodPod!)!

Study Methodology •"Subjects recruited, consent signed!•"CoreTemp pill swallowed!•"Subjects then connected to our

research hardware!•"Sat at tubside for 6 minutes, immersed

in cool tub for 24 min, rest out for 12 minutes, neutral immersion for 24 min, rest out for 12 min, warm tub for 24 min, recovery for 12 min.!

HRV & Health •" Autonomic imbalance has been suggested to

be the final common pathway in many diseases!

•" Highly correlated with cardiovascular health!•" Associated with diabetes, inflammatory

processes, and immune dysfunction!•" An increase in parasympathetic tone

decreases release of inflammatory cytokines, & increased sympathetic tone increases them!

HRV Analysis •" Computerized breakdown into frequency

spectra via fast Fourier Transformation:!–" Ultra-low frequency (<0.04 HZ) (respiratory)!–" Very low frequency (0.04HZ) (sympathetic activity)!–" Low frequency (0.04-0.15HZ)(sympathetic &GI)!–" High frequency (0.15-0.4HZ) (parasympathetic

activity)!–" Sympathetic!–" Vagal (parasympathetic)!–" Sympathetic / Vagal balance!

Core Temperature Response !by Age Group!

Heart Rate Change during Immersion!

Blood Pressure Response !by Age Group!

0!

100!

200!

300!

400!

500!

600!

700!

Period 1!Period 2!Period 3! Period 1!Period 2!Period 3! Period 1!Period 2!Period 3!

Pre! Cool! Recovery! Neutral! Recovery! Warm! Recovery!

Blo

od P

erfu

sion

Uni

ts!

Older Group!

Younger Group!

VLF Power Spectral Display by Age Group!

HF Power Spectral Display by Age Group!

Sympathovagal Balance by Age Group!

Study Result Summary

•"There seems to be a very significant effect of warm water immersion upon the autonomic nervous system!

•"That effect seems to enhance the balance between parasympathetic and sympathetic components, and is likely one of the major changes that create the feeling of relaxation in warm water.!

Results Summary cont. •"The increase in autonomic balance did not

happen in cooler water temperatures!•"Sympathetic activation occurred in both

cool and neutral temperatures, but not in warm!

•"The changes noted were quite consistent across all of the subjects tested!

Results Summary, con’t •" Systolic pressures remained quite constant through

all 3 immersion phases!•" Diastolic pressures declined through the 3 phases!•" Heart rates remained stable until climbing during the

mid-point of warm water immersion!•" Core temperatures also rose during this latter cycle,

but only by less than 1°C on average!

Study conclusions thus far •" The data we have analyzed so far indicates

that in these healthy subjects there are a number of important ANS changes that occur during warm water immersion.!

•" There seems to be a dose response (immersion time) relationship!

•" These changes may well have beneficial public health implications for warm water immersion.!

Potential Clinical Applications

•"Depression!•"Anxiety and panic disorders!•"Attention Deficit Disorder!•"Autism!•"Cardiac Rehabilitation!•"Diabetes, both Types I & II!

The Unique Effects of Immersion

! " Usually lowers blood pressure!! " Reduces autonomic imbalance!! " Strengthens inspiratory musculature!! " Improves kidney function!! " Increases muscle perfusion!! " Offloads joints, and probably increases

circulation to joints!! " Enhances cardiovascular efficiency!

The National Aquatics & Sports Medicine Institute Research Team

Washington State University